This study investigated how quickly participants could develop a functional mental representation of a real-world road scene, based on briefly viewed recorded video. Using Amazon Mechanical Turk, we recruited 27 participants and collected 25k individual trials assessing the development of a percept of the road environment. This was operationalized as the duration of road video required for participants to predict which of two temporally spaced images would happen next. We found that participants could begin to build a representation of the road environment with as little as 100 ms of viewed road video and that the representation improved with additional video. These results suggest that drivers may begin to construct robust, predictive mental representations of the road environment with the briefest of glances, and the more information available to them, the more robust these representations are. While 100 ms of eyes-on-road time is insufficient to ensure safe driving, comprehension of the road environment begins in the blink of an eye.